Updated on February 7, 2024
5 min read

Fractured Cusp

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What is a Fractured Cusp?

A fractured cusp is a common dental injury that occurs when a piece of a tooth’s chewing surface breaks. The break or crack affects a portion of the tooth called the cusp. 

Cusps are the raised areas on a tooth’s chewing surface that help grind food. Each tooth has at least one cusp, and most molars have four or five.

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A cusp can fracture for many reasons, including tooth decay or injury. The severity of symptoms it will cause depends on the extent of the crack and whether the dental pulp (inner soft tissue) is exposed. 

Early diagnosis and treatment are essential for saving cracked teeth. Call your general dentist if you have a cusp fracture or other type of cracked tooth. 

Does a Fractured Cusp Hurt?

A fractured cusp doesn’t always cause pain. This is especially true if the crack only affects the chewing surface. However, a severely damaged tooth can be painful.

Some people only experience pain when chewing, and others have erratic pain that comes and goes. A cracked tooth can start hurting all by itself after a while. 

Extensive cracks can lead to infected dental pulp, which can spread to the surrounding bone and gums if left untreated.

Symptoms of a Fractured Tooth Cusp

Symptoms vary depending on the type, location, and extent of the crack. You might not notice a fracture if only the outer enamel is affected. Larger fractures can be painful and require a visit to the dentist. 

Common symptoms of a fractured tooth include:

  • Sensitivity to hot or cold
  • Sharp edge of the tooth (that can be detected by your tongue)
  • Sharp pain while chewing
  • Gum discomfort
Fractured Cusp 3-d Depiction

How is a Fractured Cusp Treated?

Treatment can help relieve pain and prevent infection from a cusp fracture. The recommended treatment depends on the severity and extent of the tooth fracture.

Treatment for a cracked cusp may include:

  • Topical oral pain medications To eliminate pain symptoms
  • Dental filling  Your dentist will place a tooth-colored filling over the broken area
  • Dental crown  A protective cap that covers the cracked tooth
  • Dental inlay or onlay  A dental restoration that’s smaller than a crown but larger than a filling
  • Root canal treatment Also called endodontic treatment, your dentist may recommend a root canal if they think the tooth can be saved
  • Tooth extraction Your dentist will pull the tooth if it can’t be saved

When is a Fractured Cusp an Emergency?

If you fracture a cusp of your tooth, don’t panic. Very few dental emergencies can’t be easily managed at home before dental visits. 

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However, early diagnosis and treatment are always important to avoid a dental emergency. 

Visit your dentist immediately if you experience any of the following:

How to Prevent Tooth Fractures

Sometimes tooth trauma is unpreventable. However, there are some things you can do to reduce your risk, including: 

  • Wear an athletic mouthguard when you play sports to avoid trauma 
  • Consider getting a custom night guard if you grind your teeth while sleeping
  • Visit your dentist regularly
  • Avoid biting into hard objects or foods

What Causes a Fractured Cusp?

Many fractured cusps occur in teeth that contain large fillings. The filling can cause tiny cracks in the tooth that weakens the cusps.2

Other common causes of a fractured cusp include:

  • Severe tooth decay 
  • Bruxism (chronic teeth grinding/clenching) 
  • Trauma 
  • Wear and tear on the tooth
  • Failed dental restorations, including dental crowns and bridges 
  • Biting into hard foods or items

How is a Fractured Cusp Diagnosed?

Dentists have different methods to diagnose cracked teeth and fractures early. These methods include:2 

  • Clinical examination — A careful examination to locate periodontal defects and damaged tooth segments.
  • Visual inspection — Visual detection of fractures and carious lesions in primary and permanent teeth. 
  • Exploratory excavation — Involves removing an existing filling or cavity or crack to determine the extent of the crack
  • Percussion test — A cracked tooth could be diagnosed with a positive response to apical percussion.
  • Dye test — Fracture lines can be highlighted with methylene blue or gentian violet stains.
  • Transillumination — Involves shining a light over the affected area for abnormalities.
  • Bite test — Involves biting onto different materials to determine the location and severity of a fracture. 
  • Radiograph — Uses X-rays and bitewing imaging to determine overall tooth status.

Do Fractured Teeth Heal Completely? 

If you have a fractured tooth, it will not heal on its own. Unlike broken bones, teeth require some restoration treatment.  

Once treated, most cracked teeth continue to function normally. The crack can worsen without treatment, resulting in pain, infection, or tooth loss.

More Reading


A fractured cusp happens when the top portion of the tooth cracks or breaks. This can result from an injury, an existing filling, or tooth decay. Other types of cracks can affect teeth, but they are usually treatable.

A fractured or cracked tooth can cause pain, discomfort, and sensitivity. If left untreated, it can lead to tooth loss and infection.

While fractures don’t always cause pain, a severe fracture can be painful. A fractured tooth cannot heal on its own and will require some type of treatment.

Last updated on February 7, 2024
6 Sources Cited
Last updated on February 7, 2024
All NewMouth content is medically reviewed and fact-checked by a licensed dentist or orthodontist to ensure the information is factual, current, and relevant.

We have strict sourcing guidelines and only cite from current scientific research, such as scholarly articles, dentistry textbooks, government agencies, and medical journals. This also includes information provided by the American Dental Association (ADA), the American Association of Orthodontics (AAO), and the American Academy of Pediatrics (AAP).
  1. Cracked teeth.” American Association of Endodontists, nd.
  2. Zidane, B. “Recent Advances in the Diagnosis of Enamel Cracks: A Narrative Review.” Diagnostics (Basel, Switzerland), 2022.
  3. Kakka, A., et al. “Treatment of cracked teeth: A comprehensive narrative review.” Clinical and experimental dental research, 2022.
  4. Lee, T., et al. “Characteristics, Treatment, and Prognosis of Cracked Teeth: A Comparison with Data from 10 Years Ago.” European Journal of Dentistry, 2021.
  5. Zhang, C., et al. “A method of crack detection based on digital image correlation for a simulated cracked tooth.” BMC oral health, 2021.
  6. Morimoto. S., et al. “Risk Factors Associated with Cusp Fractures in Posterior Permanent Teeth—A Cross-Sectional Study.” Applied Sciences, 2021.
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